/**
 * 全选按钮
 * @param obj
 */
function selectAll(obj){
	var checkboxes = document.getElementsByName('select_item');
	for(var i = 0; i < checkboxes.length; i++) {
		var checkbox = checkboxes[i];
		if(!$(obj).get(0).checked) {
			checkbox.checked = false;
		} else {
			checkbox.checked = true;
		}
	}
}
	
/**
 * 单选按钮
 * @param obj
 */
function chooseItem(obj){
	var hasSelected = $(obj).hasClass("checked_tr");
	$(obj)[hasSelected ? "removeClass" : "addClass"]("checked_tr").find(":checkbox").prop("checked", !hasSelected);
}
